Nicotinamide mononucleotide mitigates hyperoxia-aggravated septic lung injury via the GPx4-mediated anti-ferroptosis signaling pathway in alveolar epithelial cells

BACKGROUND

The molecular mechanisms and optimal treatment strategies underlying hyperoxia-aggravated septic lung injury remain elusive. We explored the effects and mechanisms of nicotinamide mononucleotide (NMN) on hyperoxia-aggravated septic lung injury.

METHODS

The rat and cellular models of sepsis-induced lung injury were established and subjected to hyperoxygenation treatment, followed by treatment with NMN, ferroptosis promoter, or inhibitor separately. The extent of lung injury was assessed based on histological examination, lung histological injury scores, wet/dry weight ratio of lung tissues, oxygenation indexes, TNF-ɑ and IL-6 levels, and cell viability. Meanwhile, ferroptosis was assessed through various methods. The levels of glutathione peroxidase 4 (GPx4) and 4-hydroxynonenal (4-HNE) in lung tissues were determined by immunohistochemistry, while iron deposition was evaluated using Prussian blue staining. Fe2+, MDA, and GSH levels were also detected with the respective kits. The reactive oxygen species (ROS) level was measured by flow cytometry and immunofluorescence techniques. The protein and mRNA levels of GPx4 and ACSL4 were also detected. The relationship between sirtuin 6 (SIRT6) and GPx4 was clarified by using SIRT6 inhibitor and activator, as well as in combination with sh-GPx4.

RESULTS

Hyperoxia exacerbated lung injury in rats subjected to cecal ligation and puncture (CLP). Hyperoxia also intensified damage to alveolar epithelial cells (AECs) in a lipopolysaccharide (LPS) model. However, NMN ameliorated these detrimental effects. Furthermore, LPS + Hyperoxia treatment significantly upregulated Fe2+, MDA, ROS, and ACSL4 levels, exacerbating oxidative damage. Also, LPS + Hyperoxia treatment downregulated GSH and GPx4 levels, thereby reducing antioxidant capacity. Additionally, Erastin, a ferroptosis promoter, further intensified oxidative stress damage and inflammatory response. However, ferroptosis inhibitor Fer-1 alleviated this damage. Similarly, NMN inhibited ferroptosis in hyperoxia-aggravated septic lung injury. Co-treatment with NMN and sh-GPx4 reversed the protective effect of NMN against LPS-stimulated injury exacerbated by hyperoxia in AECs. NMN supplementation increased SIRT6 expression in AECs. SIRT6 inhibition decreased GPx4 expression and raised ferroptosis markers, while SIRT6 activation had opposite effects. Co-treatment with SIRT6 activator and sh-GPx4 reversed the inhibitory effect on ferroptosis.

CONCLUSION

Hyperoxia aggravates septic lung injury by inducing ferroptosis of AECs. NMN can mitigate hyperoxia-aggravated septic lung injury by up-regulating GPx4 through increasing SIRT6 and inhibiting ferroptosis of AECs.

Tilianin regulates the proliferation, invasion and tumor immune microenvironment of thyroid cancer cells through the TLR4/NF-κB axis

Thyroid cancer is the most prevalent form of endocrine malignancy. Tilianin has demonstrated anti-tumor properties in ovarian cancer and non-small cell lung cancer (NSCLC), while its effects on thyroid cancer progression remain elusive. Hence, this research explored the role of Tilianin in thyroid cancer development and clarified the underlying mechanisms. The findings indicated that Tilianin reduced cell viability of TPC-1 (IC50 = 38.97 μM) and IHH4 (IC50 = 27.69 μM) cells dose-dependently and inhibited the expression of Ki-67. Additionally, Tilianin impaired the invasion capacity of TPC-1 and IHH4 cells, decreased the PD-L1 level, strengthened the CD8+T cell viability, and elevated the secretions of IFN-γ, IL-2, and TNF-α in CD8+T cells. Furthermore, Tilianin could suppress the activation of the TLR4/NF-κB pathway. The inhibitory effects of Tilianin on TPC-1 cell proliferation, invasion, and immune escape were reversed by overexpression of TLR4. In vivo, oral administration of Tilianin restrained thyroid cancer tumor growth, reduced the levels of Ki-67, PD-L1, TLR4, and p-NF-κB, and increased CD8+ T cell levels. In summary, Tilianin effectively restrained thyroid cancer cell proliferation, invasion, and tumor immune microenvironment through inactivating the TLR4/NF-κB pathway.

β-Nicotinamide Mononucleotide Alleviates Sepsis-associated Acute Kidney Injury by Activating NAD+/SIRT3 Signaling

Acute kidney injury (AKI) following sepsis is a life-threatening condition that portends higher mortality. β-Nicotinamide mononucleotide (β-NMN), a crucial nicotinamide adenine dinucleotide (NAD+) precursor, exhibits the potential to against sepsis. We aimed to elucidate the effect of β-NMN on septic AKI. A cecal ligation and perforation (CLP)-induced sepsis-associated AKI mice model and a lipopolysaccharide (LPS)-triggered HK-2 cell model were established. Renal histopathology in mice with septic AKI without or with β-NMN treatment was detected using H&E staining. The contents of serum creatinine (Scr), blood urea nitrogen (BUN) and renal NAD+ were assessed with kits. Inflammation was evaluated by detecting the concentrations of TNF-α, IL-1β and IL-6 using ELISA kits. Besides, TUNEL assay was used to examine apoptosis and apoptosis-associated proteins was measured using immunoblotting. Additionally, expression of genes in sirtuins (SIRTs) family in renal tissues was tested using RT-qPCR. HK-2 cell viability was detected using CCK-8 assy. Finally, SIRT3 was silenced to carry out the rescue experiments. As a result, NAD+ level was decreased in kidney tissues of mice with sepsis-associated AKI and HK-2 cells treated with LPS. β-NMN treatment increased NAD+ level and alleviated the inflammation and apoptosis in renal tissues. It could be observed that SIRT3 expression was notably downregulated in vivo and in vitro, which was upregulated by β-NMN supplementation. Further, interfering with SIRT3 expression mitigated the protective effects of β-NMN on the inflammation and apoptosis of HK-2 cells under LPS conditions. In summary, β-NMN alleviates sepsis-associated AKI by activating NAD+/SIRT3 signaling. Our findings provide evidence of β-NMN supplementation on improvement of sepsis-associated AKI.

MiRNA affects the advancement of breast cancer by modulating the immune system's response

Breast cancer (BC), which is the most common tumor in women, has greatly endangered women's lives and health. Currently, patients with BC receive comprehensive treatments, including surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted therapy. According to the latest research, the development of BC is closely related to the inflammatory immune response, and the immunogenicity of BC has steadily been recognized. As such, immunotherapy is one of the promising and anticipated forms of treatment for BC. The potential values of miRNA in the diagnosis and prognosis of BC have been established, and aberrant expression of associated miRNA can either facilitate or inhibit progression of BC. In the tumor immune microenvironment (TME), miRNAs are considered to be an essential molecular mechanism by which tumor cells interact with immunocytes and immunologic factors. Aberrant expression of miRNAs results in reprogramming of tumor cells actively, which may suppress the generation and activation of immunocytes and immunologic factors, avoid tumor cells apoptosis, and ultimately result in uncontrolled proliferation and deterioration. Therefore, through activating and regulating the immunocytes related to tumors and associated immunologic factors, miRNA can contribute to the advancement of BC. In this review, we assessed the function of miRNA and associated immune system components in regulating the advancement of BC, as well as the potential and viability of using miRNA in immunotherapy for BC.

Ca2+ transfer via enhancing ER-Mito coupling contributed to BDE-47- induced hippocampal neuronal necroptosis and cognitive dysfunction

2,2,4,4-Tetrabromodiphenyl ether (BDE-47), a ubiquitous environmental pollutant, has gained increasing attention due to its high level in biological samples and potential neurotoxicity. Recent studies have indicated that the receptor interacting protein kinase 1 (RIPK1)-mediated necroptosis is implicated in BDE-47 cytotoxicity. However, little is known about the underlying mechanism and whether the necroptosis participates in BDE-47-induced neuronal injury and cognitive impairment. Our results indicated that exposure to BDE-47 triggered RIPK1-dependent neuronal necroptosis in mice hippocampi and HT-22 mouse hippocampal neurons. Necrostain-1 (Nec-1), a specific RIPK1 inhibitor, suppressed the RIPK1/RIPK3/mixed lineage kinase-like domain protein (MLKL) signaling and rescued neuronal survival in BDE-47-treated HT-22 neurons. Mechanically, increased mitochondrial Ca2+ influx precipitated the opening of the mitochondrial permeability transition pore (mPTP), leading to occurrence of hippocampal neuronal necroptosis under BDE-47 stress. BDE-47 exposure induced excessive mitochondria-associated endoplasmic reticulum membranes (MAMs) formation and promoted ER-to-mitochondria Ca2+ transfer, while diminishing ER-mitochondrial contacts by Glucose-regulated protein 75 (Grp75)-deficiency remarkably prevented mitochondria Ca2+ overload and opening of mPTP as well as neuronal necroptosis. Notably, Nec-1 pre-treatment could substantially mitigate neuronal/synaptic damage and cognitive impairment in BDE-47-exposed mice. Collectively, these data suggest that BDE-47 exposure intensified endoplasmic reticulum (ER)-mitochondrial (Mito) contact and facilitated Ca2+ transfer from ER towards mitochondria, resulting in mPTP opening-mediated hippocampal neuronal necroptosis and subsequent cognitive dysfunction. Our study shed new light on the mechanisms underlying BDE-47 neurotoxicity and provided a novel therapeutic strategy through targeting RIPK1 kinase activity.

Circular RNA-OGDH Promotes PANoptosis in Diabetic Cardiomyopathy: A Novel Mechanistic Insight

Diabetic cardiomyopathy (DCM) is a myocardial structural and functional abnormality directly caused by diabetes and is a principal factor in the development of cardiovascular complications in patients with diabetes. The study aims to investigate the role of circOGDH in the development of DCM and elucidate its precise underlying mechanisms. We established two well-characterised diabetic mouse models, C57BL/6J and db/db, and assessed cardiac function by serum lactate dehydrogenase activity assay and echocardiography, as well as quantitative histological analyses of the extent of myocardial fibrosis in combination with HE staining and Masson trichrome staining. The results demonstrated that there was a significant upregulation of circOGDH expression levels in myocardial tissues of mice in a diabetic state, accompanied by increased expression of key effector proteins of PANoptosis. It is noteworthy that the knockdown of circOGDH led to a substantial enhancement in cardiac function indices, a reduction in the area of myocardial fibrosis, and the effective inhibition of the PANoptosis process in myocardial tissues. In the H9c2 cells model, silencing of circOGDH also exhibited significant protective effects, including increased cell survival, reduced levels of oxidative stress, decreased apoptosis, and suppressed expression of PANoptosis-related proteins. Subsequent employing RNA pull-down, RNA immunoprecipitation and co-immunoprecipitation experimental methods have elucidated, for the first time, the molecular mechanism by which circOGDH specifically targets and regulates RIPK3 through the HMGB1 signalling pathway. The present study definitively demonstrated that up-regulation of circOGDH expression in a diabetic state could exacerbate pathological damage in diabetic cardiomyopathy by activating the HMGB1/RIPK3 signalling pathway.

Tumor-infiltrated double-negative regulatory T cells predict outcome of T cell-based immunotherapy in nasopharyngeal carcinoma

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has demonstrated clinical success in solid tumors. We analyze 47 TIL infusion products and 62 pretreatment tumor microenvironments (TMEs) from a randomized phase 2 clinical study of concurrent chemoradiotherapy plus TIL-ACT (NCT02421640). Using single-cell and bulk RNA sequencing along with flow cytometry, we identify 14 CD3+ T cell clusters within 26 TIL infusion products: 11 CD3+CD8+ TILs, 2 CD3+CD4+ TILs, and 1 CD3+CD8-CD4- double-negative (DN) TIL. (DN) TILs, significantly associated with poor TIL-ACT outcomes, exhibit an activated regulatory T cell-like phenotype and include two CD56+ and four CD56- subsets. Among them, CD56-KZF2+ (DN) TILs are predominantly suppressive. (DN) TILs inhibit CD8+ TIL expansion via Fas-FasL, transforming growth factor β (TGF-β), and interleukin (IL)-10 signaling. Distinct CD8+ T subsets differentially impact on TIL-ACT outcomes, while 9 baseline TME gene signatures and 14 intracellular T cell genes hold prognostic value. Our findings identify predictive TIL subsets and biomarkers for TIL-ACT outcomes.

Harnessing Folate Receptors: A Comprehensive Review on the Applications of Folate-Adorned Nanocarriers for the Management of Melanoma

The advancement in exclusively tailored therapeutic delivery systems has escalated a great deal of interest in targeted delivery to augment therapeutic efficacy and to lessen adverse effects. The targeted delivery approach promisingly helps to surmount the unmet clinical needs of conventional therapies, including chemoresistance, limited penetration, and side effects. In the case of melanoma, various receptors were overexpressed on the tumor site, among which folate receptor (FR) targeting is considered to be a progressive approach for managing melanoma. FRs are the macromolecules of the glycosyl phosphatidylinositol-attached protein that possess globular assembly with a greater affinity toward specific ligands. So, the functional ligands can be utilized to design targeted nanocarriers (NCs) that can effectively bind to overexpressed FRs. Hence, folate-adorned NCs (FNCs) offer various benefits such as site-specific targeting, cargo protection, and minimizing toxicity. This review focuses on the insights and implications of FRs, targeting FRs, and mechanisms, challenges, and advantages of FNCs. Further, the applications of various FNCs, such as liposomes, polymeric NCs, albumin nanoparticles, inorganic NCs, liquid crystalline nanoparticles, and nanogels, have been elaborated for melanoma therapy. Likewise, the potential of FNCs in immunotherapy, photodynamic therapy, chemotherapy, gene therapy, photothermal therapy, and tumor imaging has been exhaustively discussed. Furthermore, translational hurdles and potential solutions are discussed in detail. The present review is expected to give thoughtful ideas to researchers, industry stakeholders, and formulation scientists for the efficacious development of FNCs.

Mechanisms of CD8+ T cell exhaustion and its clinical significance in prognosis of anti-tumor therapies: A review

In recent years, immunotherapy has gradually become one of the main strategies for cancer treatment, with immune checkpoint inhibitors (ICIs) offering new possibilities for tumor therapy. However, some cancer patients exhibit low responses and resistance to ICIs treatment. T cell exhaustion, a process associated with tumor progression, refers to a subset of T cells that progressively lose effector functions and exhibit increased expression of inhibitory receptors. These exhausted T cells are considered key players in the therapeutic efficacy of immune checkpoint inhibitors. Therefore, understanding the impact of T cell exhaustion on tumor immunotherapy and the underlying mechanisms is critical for improving clinical treatment outcomes. Several elegant studies have provided insights into the prognostic value of exhausted T cells in cancers. In this review, we highlight the process of exhausted T cells and its predictive value in various cancers, as well as the relevant mechanisms behind it, providing new insights into the immunotherapy of cancer.

Receptor-interacting protein kinase 3: A macromolecule with multiple cellular actions and its perspective in the diagnosis and treatment of heart disease

Receptor-interacting protein kinase 3 (RIP3), a serine/threonine kinase of the RIP family, has emerged as a critical regulator of necroptosis, a necrosis-like form of cell demise. However, recent research has revealed that overactivated RIP3 might also be involved in the regulation of other cell death forms, such as pyroptosis, autophagy, mitochondrial permeability transition pore (mPTP)-necrosis and ferroptosis, and operates in diverse cellular compartments. RIP3 can therefore affect inflammation, oxidative stress and energy metabolism, further underscoring its pivotal role in cellular homeostasis. Furthermore, elevated circulating levels of RIP3 have been observed in cardiac disorders such as heart failure, myocardial infarction, and coronary artery disease and might correlate with disease severity and worse prognostic outcomes. On the contrary, the pharmacological inhibition of RIP3 has shown protective effects due to complex mechanisms involving necroptosis retardation, prevention of immune cell infiltration, and mitigation of cardiac cells mitochondrial damage. A detailed understanding of the complexity of RIP3's function in the heart may favour its diagnostic potential and lead to the development of future therapeutic interventions.

Unraveling immunosenescence in sepsis: from cellular mechanisms to therapeutics

Sepsis is a life-threatening multiple organ dysfunction resulting from a dysregulated host response to infection, and patients with sepsis always exhibit a state of immune disorder characterized by both overwhelming inflammation and immunosuppression. The aging of immune system, namely "immunosenescence", has been reported to be correlated with high morbidity and mortality in elderly patients with sepsis. Initially, immunosenescence was considered as a range of age-related alterations in the immune system. However, increasing evidence has proven that persistent inflammation or even a short-term inflammatory challenge during sepsis could trigger accelerated aging of immune cells, which might further exacerbate inflammatory cytokine storm and promote the shift towards immunosuppression. Thus, premature immunosenescence is found in young sepsis individuals, which further aggravates immune disorders and induces the progression of sepsis. Furthermore, in old sepsis patients, the synergistic effects of both sepsis and aging may cause immunosenescence-associated alterations more significantly, resulting in more severe immune dysfunction and a worse prognosis. Therefore, it is necessary to explore the potential therapeutic strategies targeting immunosenescence during sepsis.

Role of Tumor Necrosis Factor in Tuberculosis

Tumor necrosis factor (TNF) is a key immunoregulatory cytokine with a dual role in the host response to Mycobacterium tuberculosis. While essential for granuloma formation, macrophage activation, and containment of latent infection, TNF can also contribute to tissue damage and immune pathology. This review systematically analyzes over 300 peer-reviewed studies published between 1980 and 2024, highlighting the molecular and cellular mechanisms of TNF action in tuberculosis (TB). Particular attention is given to TNF receptor signaling pathways, the balance between protective and pathological immune responses, and the modulation of TNF activity during anti-TNF therapy in patients with autoimmune diseases. We discuss how different TNF inhibitors vary in their capacity to interfere with host defense mechanisms, with monoclonal antibodies carrying a higher reactivation risk than receptor-based agents. To enhance conceptual clarity, we provide newly developed schematic representations that integrate current knowledge on TNF-driven immune dynamics, including its interaction with other cytokines, effects on granuloma stability, and role in intracellular bacterial control. Understanding the pleiotropic functions of TNF in tuberculosis pathogenesis is crucial for developing safe immunomodulatory strategies and optimizing the clinical management of patients at risk of latent TB reactivation.

Molecular Insights into Oxidative-Stress-Mediated Cardiomyopathy and Potential Therapeutic Strategies

Cardiomyopathies comprise a heterogeneous group of cardiac disorders characterized by structural and functional abnormalities in the absence of significant coronary artery disease, hypertension, valvular disease, or congenital defects. Major subtypes include hypertrophic, dilated, arrhythmogenic, and stress-induced cardiomyopathies. Oxidative stress (OS), resulting from an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, has emerged as a key contributor to the pathogenesis of these conditions. ROS-mediated injury drives inflammation, protease activation, mitochondrial dysfunction, and cardiomyocyte damage, thereby promoting cardiac remodeling and functional decline. Although numerous studies implicate OS in cardiomyopathy progression, the precise molecular mechanisms remain incompletely defined. This review provides an updated synthesis of current findings on OS-related signaling pathways across cardiomyopathy subtypes, emphasizing emerging therapeutic targets within redox-regulatory networks. A deeper understanding of these mechanisms may guide the development of targeted antioxidant strategies to improve clinical outcomes in affected patients.

Designer Organs: Ethical Genetic Modifications in the Era of Machine Perfusion

Gene therapy is a rapidly developing field, finally yielding clinical benefits. Genetic engineering of organs for transplantation may soon be an option, thanks to convergence with another breakthrough technology, ex vivo machine perfusion (EVMP). EVMP allows access to the functioning organ for genetic manipulation prior to transplant. EVMP has the potential to enhance genetic engineering efficiency, improve graft survival, and reduce posttransplant complications. This will enable genetic modifications with a vast variety of applications, while raising questions on the ethics and regulation of this emerging technology. This review provides an in-depth discussion of current methodologies for delivering genetic vectors to transplantable organs, particularly focusing on the enabling role of EVMP. Organ-by-organ analysis and key characteristics of various vector and treatment options are assessed. We offer a road map for research and clinical translation, arguing that achieving scientific benchmarks while creating anticipatory governance is necessary to secure societal benefit from this technology.

Recent progress in topical and transdermal approaches for melanoma treatment

The global incidence of melanoma, the most lethal form of skin cancer, continues to escalate, emphasizing the urgent need for more effective therapeutic strategies. This review assesses the latest advancements in topical and transdermal drug delivery systems, positioning them as promising alternatives. These systems allow for the direct application of therapeutic agents to tumor sites, enhancing drug effectiveness, improving patient compliance, and reducing systemic toxicity. Specifically, innovations such as nanoparticles, microneedles, and vesicular systems are explored for their potential to optimize topical and localized drug delivery. By incorporating a graphical overview of these drug delivery vehicles, we visually underscore their roles in enhancing therapeutic outcomes across various treatment categories such as chemotherapy, immunotherapy, phototherapy, phytotherapy, and targeted therapy. This article critically evaluates recent breakthroughs, addresses the current challenges faced by researchers, and explores the future directions of topical and transdermal approaches in melanoma management. By presenting a summary of the latest research and predicting future trends, this review aims to inform ongoing developments and encourage further innovation in strategies for treating melanoma.

Signal Converter-Based Therapy Platform Promoting Aging Bone Healing by Improving Permeability of the Mitochondrial Membrane

The aging microenvironment promotes persistent inflammation and loss of intrinsic regenerative capacity. These are major obstacles to effective bone tissue repair in older adults. This study aims to explore how physical thermal stimulation can effectively delay the bone marrow mesenchymal stem cells (BMSCs) aging process. Based on this, an implantable physical signal-converter platform is designed as a therapeutic system that enables stable heat signals at the bone injury site under ultrasound stimulation (US). It is found that the therapeutic platform controllably reduces the mitochondrial outer membrane permeabilization of aging BMSCs, bidirectionally inhibiting mitochondrial reactive oxygen species and mitochondrial DNA (mtDNA) leakage. The leakage ratio of mtDNA decreases by 22.7%. This effectively mitigates the activation of the cGAS-STING pathway and its downstream NF-κB signaling induced by oxidative stress in aging BMSCs, thereby attenuating the pathological advancement of chronic inflammation. Thus, it effectively restores the metabolism and osteogenic differentiation of aging BMSCs in vitro, which is further confirmed in a rat model. In the GMPG/US group, the bone mineral density increases 2-3 times at 4 weeks in the rats femoral defect model. Therefore, this ultrasound-based signal-conversion platform provides a promising strategy for aging bone defect repair.

Adenosine triphosphate-induced cell death in heart failure: Is there a link?

Heart failure (HF) has emerged as one of the foremost global health threats due to its intricate pathophysiological mechanisms and multifactorial etiology. Adenosine triphosphate (ATP)-induced cell death represents a novel form of regulated cell deaths, marked by cellular energy depletion and metabolic dysregulation stemming from excessive ATP accumulation, identifying its uniqueness compared to other cell death processes modalities such as programmed cell death and necrosis. Growing evidence suggests that ATP-induced cell death (AICD) is predominantly governed by various biological pathways, including energy metabolism, redox homeostasis and intracellular calcium equilibrium. Recent research has shown that AICD is crucial in HF induced by pathological conditions like myocardial infarction, ischemia-reperfusion injury, and chemotherapy. Thus, it is essential to investigate the function of AICD in the pathogenesis of HF, as this may provide a foundation for the development of targeted therapies and novel treatment strategies. This review synthesizes current advancements in understanding the link between AICD and HF, while further elucidating its involvement in cardiac remodeling and HF progression.

Regulated cell death and DAMPs as biomarkers and therapeutic targets in normothermic perfusion of transplant organs. Part 1: their emergence from injuries to the donor organ

This Part 1 of a bipartite review commences with a succinct exposition of innate alloimmunity in light of the danger/injury hypothesis in Immunology. The model posits that an alloimmune response, along with the presentation of alloantigens, is driven by DAMPs released from various forms of regulated cell death (RCD) induced by any severe injury to the donor or the donor organ, respectively. To provide a strong foundation for this review, which examines RCD and DAMPs as biomarkers and therapeutic targets in normothermic regional perfusion (NRP) and normothermic machine perfusion (NMP) to improve outcomes in organ transplantation, key insights are presented on the nature, classification, and functions of DAMPs, as well as the signaling mechanisms of RCD pathways, including ferroptosis, necroptosis, pyroptosis, and NETosis. Subsequently, a comprehensive discussion is provided on major periods of injuries to the donor or donor organs that are associated with the induction of RCD and DAMPs and precede the onset of the innate alloimmune response in recipients. These periods of injury to donor organs include conditions associated with donation after brain death (DBD) and donation after circulatory death (DCD). Particular emphasis in this discussion is placed on the different origins of RCD-associated DAMPs in DBD and DCD and the different routes they use within the circulatory system to reach potential allografts. The review ends by addressing another particularly critical period of injury to donor organs: their postischemic reperfusion following implantation into the recipient-a decisive factor in determining transplantation outcome. Here, the discussion focuses on mechanisms of ischemia-induced oxidative injury that causes RCD and generates DAMPs, which initiate a robust innate alloimmune response.

Decoding immune cell interactions during cardiac allograft vasculopathy: insights derived from bioinformatic strategies

Chronic allograft vasculopathy (CAV) is a major cause of late graft failure in heart transplant recipients, characterized by progressive intimal thickening and diffuse narrowing of the coronary arteries. Unlike atherosclerosis, CAV exhibits a distinct cellular composition and lesion distribution, yet its pathogenesis remains incompletely understood. A major challenge in CAV research has been the limited application of advanced "-omics" technologies, which have revolutionized the study of other vascular diseases. Recent advancements in single-cell and spatial transcriptomics, proteomics, and metabolomics have begun to uncover the complex immune-endothelial-stromal interactions driving CAV progression. Notably, single-cell RNA sequencing has identified previously unrecognized immune cell populations and signaling pathways implicated in endothelial injury and vascular remodeling after heart transplantation. Despite these breakthroughs, studies applying these technologies to CAV remain sparse, limiting the translation of these insights into clinical practice. This review aims to bridge this gap by summarizing recent findings from single-cell and multi-omic approaches, highlighting key discoveries, and discussing their implications for understanding CAV pathogenesis.

Best practices of heart transplantation in mice

Heart transplantation in mice has served as a reliable in vivo model in transplant research worldwide for more than half a century. It is not only useful for addressing cardiac graft-specific questions but also provides mechanistic insights and therapeutic strategies that have a broad impact across all solid organ transplants. Compared to other mouse models of solid organ transplantation, such as kidney, lung, or small intestine transplants, the surgical techniques to perform mouse heart transplantation (mHT) are relatively easy to master, and the graft heartbeat offers a simple means to evaluate transplant viability. However, as with other in vivo mouse models, mHT has distinct strengths and limitations. Multiple factors can influence the accuracy and reproducibility of the results, including microsurgical techniques and microsurgeons' skills, postoperative monitoring methodologies, mouse strain combinations, and sex/age. As innovative biotechnologies continue to emerge, the future holds many opportunities for preclinical research utilizing the mHT model. It is therefore imperative to provide the field with optimized mHT protocols and maintain standard reporting requirements. This minireview provided a concise summary and recommendations for standardized practices to ensure the accuracy, reproducibility, and translational value of findings generated from the mHT model.

Meta-analysis of niacin and NAD metabolite treatment in infectious disease animal studies suggests benefit but requires confirmation in clinically relevant models

Disruption of nicotinamide adenine dinucleotide (NAD) biosynthesis and function during infection may impair host defenses and aggravate inflammatory and oxidative organ injury. Increasingly, studies are investigating whether niacin or NAD metabolite treatment is beneficial in infection and sepsis animal models. We examined whether this preclinical experience supports clinical trials. A systematic review of three data bases was conducted through 2/29/2024 and a meta-analysis was performed comparing niacin or NAD metabolite treatment to control in adult animal models employing microbial challenges. Fifty-six studies met inclusion criteria, with 24 published after 2019. Most studies employed mouse (n = 40 studies) or rat (n = 12) models and administered either a bacterial toxin (n = 28) or bacterial (n = 19) challenge. Four and three studies employed viral or fungal challenges respectively. Studies investigated an NAD metabolite alone (n = 44), niacin alone (n = 9), or both (n = 3), usually administered before or within 24h after challenge (n = 50). Only three and four studies included standard antimicrobial support or started treatment > 24h after challenge respectively. In similar patterns with differing animal types (p ≥ 0.06), compared to control across those studies investigating the parameter, niacin or NAD treatment decreased the odds ratio of mortality [95% confidence interval (CI)] [0.28 (0.17, 0.49)] and in blood or tissue increased antioxidant levels [standardized mean differences (95%CI)] (SMD) [3.61 (2.20,5.02)] and decreased levels of microbes [- 2.44 (- 3.34, - 1.55)], histologic and permeability organ injury scoring [- 1.62 (- 2.27, - 0.98) and - 1.31(- 1.77, - 0.86) respectively], levels of TNFα, IL-6 and IL-1β [- 2.47 (- 3.30, - 1.64), - 3.17 (- 4.74, - 1.60) and - 8.44 (- 12.4, - 4.5) respectively] and myeloperoxidase (MPO) [- 1.60 (- 2.06, - 1.14)], although with significant, primarily quantitative heterogeneity for each (I2 ≥ 53%, p < 0.01) except MPO. Treatment increased blood or tissue NAD+ levels and decreased chemical organ injury measures and oxidation markers but differently comparing species (p ≤ 0.05). Only 2 and 9 survival studies described power analyses or animal randomization respectively and no study described treatment or non-histologic outcome measure blinding. Among survival studies, Egger's analysis (p = 0.002) suggested publication bias. While suggestive, published animal studies do not yet support clinical trials testing niacin and NAD metabolite treatment for infection and sepsis. Animal studies simulating clinical conditions and with randomized, blinded designs are needed to investigate this potentially promising therapeutic approach.

Life-threatening risk factors contribute to the development of diseases with the highest mortality through the induction of regulated necrotic cell death

Chronic diseases affecting the cardiovascular system, diabetes mellitus, neurodegenerative diseases, and various other organ-specific conditions, involve different underlying pathological processes. However, they share common risk factors that contribute to the development and progression of these diseases, including air pollution, hypertension, obesity, high cholesterol levels, smoking and alcoholism. In this review, we aim to explore the connection between four types of diseases with different etiologies and various risk factors. We highlight that the presence of risk factors induces regulated necrotic cell death, leading to the release of damage-associated molecular patterns (DAMPs), ultimately resulting in sterile inflammation. Therefore, DAMP-mediated inflammation may be the link explaining how risk factors can lead to the development and maintenance of chronic diseases. To explore these processes, we summarize the main cell death pathways activated by the most common life-threatening risk factors, the types of released DAMPs and how these events are associated with the pathophysiology of diseases with the highest mortality. Various risk factors, such as smoking, air pollution, alcoholism, hypertension, obesity, and high cholesterol levels induce regulated necrosis. Subsequently, the release of DAMPs leads to chronic inflammation, which increases the risk of many diseases, including those with the highest mortality rates.

Metabolic Stability and Targeted Delivery of Oligonucleotides: Advancing RNA Therapeutics Beyond The Liver

Oligonucleotides have emerged as a formidable new class of nucleic acid therapeutics. Fully modified oligonucleotides exhibit enhanced metabolic stability and display successful clinical applicability for targets formerly considered "undruggable". Accumulating studies show that conjugation to targeting modalities of stabilized oligonucleotides, especially small interfering RNAs (siRNAs), has enabled robust delivery to intended cells/tissues. However, the major challenge in the field has been the stability and targeted delivery of oligonucleotides (siRNAs and antisense oligonucleotides (ASOs)) to extrahepatic tissues. In this Perspective, we review chemistry innovations and emerging delivery approaches that have revolutionized oligonucleotide drug discovery and development. We explore findings from both academia and industry that highlight the potential of oligonucleotides for indications involving different extrahepatic organs─including skeletal muscles, brain, lungs, skin, heart, adipose tissue, and eyes. In all, continued advances in chemistry coupled with conjugation-based approaches or novel administration routes will further advance the delivery of oligonucleotides to extrahepatic tissues.

The Role of Post-Translational Modifications in Necroptosis

Necroptosis, a distinct form of regulated necrosis implicated in various human pathologies, is orchestrated through sophisticated signaling pathways. During this process, cells undergoing necroptosis exhibit characteristic necrotic morphology and provoke substantial inflammatory responses. Post-translational modifications (PTMs)-chemical alterations occurring after protein synthesis that critically regulate protein functionality-constitute essential regulatory components within these complex signaling cascades. This intricate crosstalk between necroptotic pathways and PTM networks presents promising therapeutic opportunities. Our comprehensive review systematically analyzes the molecular mechanisms underlying necroptosis, with particular emphasis on the regulatory roles of PTMs in signal transduction. Through systematic evaluation of key modifications including ubiquitination, phosphorylation, glycosylation, methylation, acetylation, disulfide bond formation, caspase cleavage, nitrosylation, and SUMOylation, we examine potential therapeutic applications targeting necroptosis in disease pathogenesis. Furthermore, we synthesize current pharmacological strategies for manipulating PTM-regulated necroptosis, offering novel perspectives on clinical target development and therapeutic intervention.

Double-negative T cells in combination with ursodeoxycholic acid ameliorates immune-mediated cholangitis in mice

BACKGROUND

Primary biliary cholangitis (PBC) is a liver-specific autoimmune disease. Treatment of PBC with ursodeoxycholic acid (UDCA) is not sufficient to prevent disease progression. Our previous study revealed that the number of hepatic double-negative T cells (DNT), which are unique regulatory T cells, was reduced in PBC patients. However, whether replenishment of DNT can prevent the progression of PBC remains unclear.

METHODS

DnTGFβRII (Tg) mice and 2OA-BSA-immunized mice received DNT alone or in combination with oral UDCA. After 6-12 weeks of treatment, these mice were assessed for serological changes, liver pathological manifestations and intrahepatic immune responses.

RESULTS

Adoptive transfer of DNT alone significantly decreased serum levels of alanine transaminase (ALT), aspartate transaminase (AST), antimitochondrial antibody M2 (AMA-M2) and immunoglobulin M (IgM) in both Tg and 2OA-BSA-immunized PBC mouse models. In addition, DNT exhibited a strong killing effect on liver T cells and strong inhibition of their proliferation, but did not significantly improve the histology of PBC liver. However, combination therapy with DNT and oral UDCA predominantly ameliorated liver inflammation and significantly inhibited hepatic T and B cells. In vitro further study revealed that UDCA up-regulated the proliferation of DNT, increased the expression of the functional molecule perforin, and reduced the expression of NKG2A and endothelial cell protein C receptor (EPCR) through the farnesoid X receptor (FXR)/JNK signaling pathway in both mice and human DNT.

CONCLUSIONS

A single transfer of DNT ameliorated PBC in mice, while combination therapy of DNT with oral UDCA displayed a better efficacy, with stronger inhibition of hepatic T and B cells. This study highlights the potential application of DNT-based combination therapy for PBC, especially for UDCA non-responders.

Chronic Rejection After Kidney Transplantation

In kidney transplantation, ongoing alloimmune processes-commonly triggered by HLA incompatibilities-can trigger chronic transplant rejection, affecting the microcirculation and the tubulointerstitium. Continuous inflammation may lead to progressive, irreversible graft injury, culminating in graft dysfunction and accelerated transplant failure. Numerous experimental and translational studies have delineated a complex interplay of different immune mechanisms driving rejection, with antibody-mediated rejection (AMR) being an extensively studied rejection variant. In microvascular inflammation, a hallmark lesion of AMR, natural killer (NK) cells have emerged as pivotal effector cells. Their essential role is supported by immunohistologic evidence, bulk and spatial transcriptomics, and functional genetics. Despite significant research efforts, a substantial unmet need for approved rejection therapies persists, with many trials yielding negative outcomes. However, several promising therapies are currently under investigation, including felzartamab, a monoclonal antibody targeting the surface molecule CD38, which is highly expressed in NK cells and antibody-producing plasma cells. In an exploratory phase 2 trial in late AMR, this compound has demonstrated potential in resolving molecular and morphologic rejection activity and injury, predominantly by targeting NK cell effector function. These findings inspire hope for effective treatments and emphasize the necessity of further pivotal trials focusing on chronic transplant rejection.

Necrosis-like cell death modes in heart failure: the influence of aetiology and the effects of RIP3 inhibition

Since cell dying in heart failure (HF) may vary based on the aetiology, we examined the main forms of regulated necrosis, such as necroptosis and pyroptosis, in the hearts damaged due to myocardial infarction (MI) or pressure overload. We also investigated the effects of a drug inhibiting RIP3, a proposed convergent point for both these necrosis-like cell death modes. In rat hearts, left ventricular function, remodelling, pro-cell death, and pro-inflammatory events were investigated, and the pharmacodynamic action of RIP3 inhibitor (GSK'872) was assessed. Regardless of the HF aetiology, the heart cells were dying due to necroptosis, albeit the upstream signals may be different. Pyroptosis was observed only in post-MI HF. The dysregulated miRNAs in post-MI hearts were accompanied by higher levels of a predicted target, HMGB1, its receptors (TLRs), as well as the exacerbation of inflammation likely originating from macrophages. The RIP3 inhibitor suppressed necroptosis, unlike pyroptosis, normalised the dysregulated miRNAs and tended to decrease collagen content and affect macrophage infiltration without affecting cardiac function or structure. The drug also mitigated the local heart inflammation and normalised the higher circulating HMGB1 in rats with post-MI HF. Elevated serum levels of HMGB1 were also detected in HF patients and positively correlated with C-reactive protein, highlighting pro-inflammatory axis. In conclusion, in MI-, but not pressure overload-induced HF, both necroptosis and pyroptosis operate and might underlie HF pathogenesis. The RIP3-targeting pharmacological intervention might protect the heart by preventing pro-death and pro-inflammatory mechanisms, however, additional strategies targeting multiple pro-death pathways may exhibit greater cardioprotection.

Emerging role of PANoptosis in kidney diseases: molecular mechanisms and therapeutic opportunities

Kidney diseases represent a significant global public health challenge, characterized by complex pathogenesis, high incidence, low awareness, insufficient early screening, and substantial treatment disparities. Effective therapeutic options remain lacking. Programmed cell death (PCD), including apoptosis, pyroptosis, and necroptosis, play pivotal roles in the pathogenesis of various kidney diseases. In 2019, PANoptosis, a novel form of inflammatory cell death, was introduced, providing new insights into innate immunity and PCD research. Although research on PANoptosis in kidney diseases is still limited, identifying key molecules within PANoptosomes and understanding their regulatory roles is critical for disease prevention and management. This review summarizes the various forms of PCD implicated in kidney diseases, along with PANoptosomes activated by Z-DNA binding protein 1 (ZBP1), absent in melanoma 2 (AIM2), receptor-interacting protein kinase 1 (RIPK1), NOD-like receptor family CARD domain containing 12 (NLRP12), and NOD-like receptor family member C5 (NLRC5). It also reviews the advancements in PANoptosis research in the field of kidney diseases, particularly in renal tumors and acute kidney injuries (AKI). The goal is to establish a foundation for future research into the role of PANoptosis in kidney diseases.

Nicotinamide mononucleotide protects septic hearts in mice via preventing cyclophilin F modification and lysosomal dysfunction

Myocardial dysfunction is a decisive factor of death in septic patients. Cyclophilin F (PPIF) is a major component of the mitochondrial permeability transition pore (mPTP) and acts as a critical mPTP sensitizer triggering mPTP opening. In sepsis, decreased NAD+ impairs Sirtuin 3 function, which may prevent PPIF de-acetylation. Repletion of NAD+ with nicotinamide mononucleotide (NMN) reduces myocardial dysfunction in septic mice. In addition, administration of the mPTP inhibitor cyclosporine-A attenuated sepsis-induced myocardial dysfunction, and deletion of PPIF reduced lung and liver injuries in sepsis, leading to increased survival. It is plausible that NAD+ repletion with NMN may prevent mPTP opening in protecting septic hearts through PPIF de-acetylation and/or inhibition of mitochondrial ROS-mediated PPIF oxidation. In this study we investigated how NMN alleviated myocardial dysfunction in septic mice. Sepsis was induced in mice by injection of LPS (4 mg/kg, i.p.). Then mice received NMN (500 mg/kg, i.p.) or mito-TEMPO (0.7 mg/kg, i.p.) right after LPS injection, and subjected to echocardiography for assessing myocardial function. At the end of experiment, the heart tissues and sera were collected for analyses. In vitro experiments were conducted in neonatal mouse cardiomyocytes treated with LPS (1 µg/mL) in the presence of NMN (500 µmol/L) or mito-TEMPO (25 nmol/L). We showed that LPS treatment markedly increased mitochondrial ROS production and induced lysosomal dysfunction and aberrant autophagy in cardiomyocytes and mouse hearts, leading to inflammatory responses and myocardial injury and dysfunction in septic mice. NMN administration attenuated LPS-induced deteriorative effects. Selective inhibition of mitochondrial superoxide production with mito-TEMPO attenuated lysosomal dysfunction and aberrant autophagy in septic mouse hearts. Notably, LPS treatment significantly increased acetylation and oxidation of PPIF, which was prevented by NMN in mouse hearts. Knockdown of PPIF replicated the beneficial effects of NMN or mito-TEMPO on ROS production, lysosomal dysfunction, aberrant autophagy, and myocardial injury/dysfunction in sepsis. In addition, administration of NMN abrogated LPS-induced ATP5A1 acetylation and increased ATP5A1 protein levels and ATP production in septic mouse hearts. This study demonstrates that NMN modulates the interplay of mitochondrial ROS and PPIF in maintaining normal lysosomal function and autophagy and protecting ATP5A1 and ATP production during sepsis.

From Bench to Bladder: The Rise in Immune Checkpoint Inhibition in the Treatment of Non-Muscle Invasive Bladder Cancer

Non-muscle invasive bladder cancer (NMIBC) represents a significant clinical challenge due to its high recurrence rate and need for frequent monitoring. The current treatment modality is bacillus Calmette-Guérin (BCG) therapy combined with chemotherapy after transurethral resection of the bladder tumor (TURBT), which is highly effective in most patients. Yet, the cancer becomes resistant to these treatments in 30-40% of patients, necessitating the need for new treatment modalities. In the cancer world, the development of immune checkpoint inhibitors that target molecules, such as programmed cell death protein-1 (PD-1), its ligand, PD-L1, and Cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), have revolutionized the treatment of many cancer types. PD-1/PD-L1 and CTLA-4 are shown to be upregulated in NMIBC in certain circumstances. PD-1/PD-L1 interactions play a role in immune evasion by suppressing T cell activity within the tumor microenvironment (TME), while the binding of CTLA-4 on T cells leads to downregulation of the immune response, making these pathways potential immunotherapeutic targets in NMIBC. This review seeks to understand the role of these therapies in treating NMIBC. We explore the cellular and non-cellular immune landscape in the TME of NMIBC, including Tregs, T effector cells, macrophages, B cells, and relevant cytokines. We also discuss the biological role of PD-1/PD-L1 and CTLA-4 while covering the rationale for these immunotherapies in NMIBC. Finally, we cover key clinical trials that have studied these treatments in NMIBC clinically. Such a study will be helpful for urologists and oncologists to manage patients with NMIBC more effectively.

坏死性凋亡在糖尿病性创面愈合中的研究进展

糖尿病是一种目前临床上常见的慢性代谢性疾病，并发症多，尤其是糖尿病足可导致患者残疾，甚至死亡，具有易诊断、治疗难、治疗周期长、医疗费用高且容易复发等特点，严重影响患者的生活质量及身心健康，给个人、家庭和社会造成了沉重的负担。因此，如何提高糖尿病性创面的治愈率已成为急需解决的难题。坏死性凋亡是近年来发现的一种新型的细胞程序性死亡途径，可参与多种炎症反应。研究表明，细胞坏死性凋亡参与糖尿病的发病过程，在糖尿病性创面愈合中扮演着极其重要的作用。本文通过阐述细胞坏死性凋亡与创面相关蛋白的研究及其在糖尿病性创面中的作用机制，为临床治疗糖尿病性创面提供借鉴。

Brain injury, endocrine disruption, and immune dysregulation in HIV-positive men who have sex with men with late HIV diagnosis

Background

In the realm of public health, late human immunodeficiency virus (HIV) diagnosis remains prevalent and is associated with neuropsychiatric adverse events. However, there is limited documentation regarding the impact of late HIV diagnosis (LD) on brain integrity, neurotrophic factors, endocrine function, and immunity in HIV-positive men who have sex with men (MSM).

Methods

Participants (38 LD and 34 non-LD of MSM) underwent comprehensive infectious disease and psychiatric assessments, multimodal magnetic resonance imaging (MRI) scans, neurotrophic factors, endocrine, and immunological evaluations. Immune cell levels, along with peripheral plasma concentrations of neurotrophic factors and hormones, were measured using enzyme-linked immunosorbent assays and flow cytometry, respectively. T1-weighted images along with resting-state functional MRI were applied to assess brain function and structure while also examining correlations between imaging alterations and clinical as well as peripheral blood variables. The data for this study originated from a subset of the cohort in HIV-associated neuropsychiatric disorders research.

Results

Compared to participants in the non-LD group, those in the LD group showed a lower total gray matter volume (GMV), with reduced GMV primarily observed in the left supramarginal gyrus. Participants in the LD group exhibited differences in brain function with certain regions and decreased functional connectivity between these altered regions and connected structures. A two-way factorial analysis of variance examining the main effects and interactions between groups and neuropsychiatric disorders revealed significant main effects of LD on specific brain regions. Furthermore, we found that individuals in the LD group had higher levels of cortisol, a lower frequency of central memory T cells, and elevated expression levels of perforin in double-negative T cells. These imaging findings were significantly correlated with endocrine, immune, and clinical variables.

Conclusion

This study suggests that LD may contribute to brain injury, endocrine disruption, and immune dysregulation in HIV-positive MSM. Consequently, there is an urgent need to develop public health strategies targeting late diagnosis, with a focus on strengthening screening and early detection for high-risk populations, as well as monitoring brain injury, endocrine, and immune functions in individuals with LD, and formulating precise, individualized intervention strategies to reduce the long-term impact of LD on the health of HIV-positive MSM.

Characterization and effective expansion of CD4-CD8- TCRαβ+ T cells from individuals living with type 1 diabetes

CD4-CD8- TCRαβ+ (double-negative [DN]) T cells represent a rare T cell population that promotes immunological tolerance through various cytotoxic mechanisms. In mice, autologous transfer of DN T cells has shown protective effects against autoimmune diabetes and graft-versus-host disease. Here, we characterized human DN T cells from people living with type 1 diabetes (PWT1D) and healthy controls. We found that while DN T cells and CD8+ T cells share many similarities, DN T cells are a unique T cell population, both at the transcriptomic and protein levels. We also show that by using various cytokine combinations, human DN T cells can be expanded in vitro up to 1,000-fold (mean >250-fold) and remain functional post-expansion. In addition, we report that DN T cells from PWT1D display a phenotype comparable to that of healthy controls, efficiently expand, and are highly functional. As DN T cells are immunoregulatory and can prevent T1D in various mouse models, these observations suggest that autologous DN T cells may be amenable to therapy for the prevention or treatment of T1D.

Human colonic EVs induce murine enteric neuroplasticity via the lncRNA GAS5/miR-23/NMDA NR2B axis

Postinfectious, diarrhea-predominant, irritable bowel syndrome (PI-IBS-D) is difficult to treat owing to its unknown pathophysiology. Extracellular vesicles (EVs) derived from human colon tissue and long noncoding RNAs (lncRNAs), such as growth arrest-specific 5 (GAS5), may play key roles in the pathophysiology of PI-IBS-D. To determine whether altered colonic EV lncRNA signaling leads to gastrointestinal dysfunction and heightened visceral nociception in patients with PI-IBS-D via the GAS5/miR-23ab/NMDA NR2B axis, we conducted translational studies, including those on (a) the role of colonic EV lncRNAs in patients with PI-IBS-D, human colonoids, and PI-IBS-D tissues; (b) i.p. injection of colonic EVs from patients with PI-IBS-D into Rab27a/b-/- mice (P-EV mice) to investigate whether colonic EVs drive visceral hypersensitivity in vivo via the GAS5/miR-23ab/NMDA NR2B axis; and (c) treatment of mice with oligo-miR-23 precursors and anti-GAS5 Vivo-Morpholinos for GAS5/miR-23ab/NMDA NR2B axis mechanisms. Colonic EVs from patients with PI-IBS-D, but not from control participants, demonstrated reduced miR-23a/b expression caused by enhanced GAS5 expression, which drives increased NR2B expression. Intraperitoneal injection of anti-GAS5-Vivo-Morpholino into P-EV mice increased miR-23 levels and decreased NR2B expression and VMR to CD. EVs are internal messengers that alter gastrointestinal function and increase visceral nociception in patients with PI-IBS-D. Strategies to deliver EVs to modulate GAS5/miR-23ab/NMDA NR2B axis signaling may lead to new and innovative treatments for patients with PI-IBS-D.

The immune duality of osteopontin and its therapeutic implications for kidney transplantation

Osteopontin (OPN) is a multifunctional glycoprotein with various structural domains that enable it to perform diverse functions in both physiological and pathological states. This review comprehensively examines OPN from multiple perspectives, including its protein structure, interactions with receptors, interactions with immune cells, and roles in kidney diseases and transplantation. This review explores the immunological duality of OPN and its significance and value as a biomarker and therapeutic target in kidney transplantation. In cancer, OPN typically promotes tumor evasion by suppressing the immune system. Conversely, in immune-related kidney diseases, particularly kidney transplantation, OPN activates the immune system by enhancing the migration and activation of immune cells, thereby exacerbating kidney damage. This immunological duality may stem from different OPN splice variants and the exposure, after cleavage, of different structural domains, which play distinct biological roles in cellular interactions. Additionally, OPN has a significant biological impact posttransplantation and on chronic kidney disease and, highlighting its importance as a biomarker and potential therapeutic target. Future research should further explore the specific mechanisms of OPN in kidney transplantation to improve treatment strategies and enhance patient quality of life.

Extracellular matrix gene set and microRNA network in intestinal ischemia-reperfusion injury: Insights from RNA sequencing for diagnosis and therapy

Intestinal ischemia-reperfusion injury (IIRI) is a complex and severe pathophysiological process characterized by oxidative stress, inflammation, and apoptosis. In recent years, the critical roles of extracellular matrix (ECM) genes and microRNAs (miRNAs) in IIRI have garnered widespread attention. This review aims to systematically summarize the diagnostic and therapeutic potential of ECM gene sets and miRNA regulatory networks in IIRI. First, we review the molecular mechanisms of IIRI, focusing on the dual role of the ECM in tissue injury and repair processes. The expression changes and functions of ECM components such as collagen, elastin, and matrix metalloproteinases during IIRI progression are deeply analyzed. Second, we systematically summarize the regulatory roles of miRNAs in IIRI, particularly the mechanisms and functions of miRNAs such as miR-125b and miR-200a in regulating inflammation, apoptosis, and ECM remodeling. Additionally, this review discusses potential diagnostic biomarkers and treatment strategies based on ECM genes and miRNAs. We extensively evaluate the prospects of miRNA-targeted therapy and ECM component modulation in preventing and treating IIRI, emphasizing the clinical translational potential of these emerging therapies. In conclusion, the diagnostic and therapeutic potential of ECM gene sets and miRNA regulatory networks in IIRI provides new directions for further research, necessitating additional clinical and basic studies to validate and expand these findings for improving clinical outcomes in IIRI patients.

Thyroid Cancer-The Tumor Immune Microenvironment (TIME) over Time and Space

In thyroid cancer, the tumor immune microenvironment (TIME) plays a crucial role in cancer development, progression and response to treatment. Like many other cancers, thyroid cancer creates a complex network of interactions with immune cells directly (cell-to-cell) and via humoral mediators (i.e., cytokines). This dynamic microenvironment undergoes constant modification, which can lead to changes in the immunophenotype that might explain cancer progression, dedifferentiation and resistance to treatment. According to the cancer immunoediting hypothesis, cancerous tumors can shape their immune microenvironment to create an immunosuppressive milieu that allows them to evade classic immune surveillance. One mechanism by which this occurs is through the reprogramming of immune cells, often shifting their phenotypes from cytotoxic to regulatory. Recent research has shed light on cellular components and molecular interactions within the thyroid cancer TIME. Immune cells such as Tumor-Associated Lymphocytes (TALs), myeloid-derived suppressor cells (MDSCs), Tumor-Associated Macrophages (TAMs) and Double-Negative (DN) T cells seem to play key roles in shaping the immune response to thyroid cancer. Additionally, cytokines, chemokines and other signaling molecules contribute to the communication and regulation of immune cells within that microenvironment. By studying these interactions, researchers aim to uncover not just potential therapeutic targets but also biomarkers of thyroid cancer that could provide clues on severity and progression. Based on that knowledge, strategies such as the use of immune checkpoint inhibitors, antigen-specific targeted immunotherapies, and immunomodulatory agents are being explored to enhance the anti-tumor immune response and overcome cancer immunosuppressive mechanisms. In this review, we analyze the available literature and provide our own experience to unravel the complexity of the thyroid immune microenvironment. Continued research in this area holds promise for improving outcomes through the identification of immune markers of severity/progression of thyroid cancer and the development of innovative immunotherapeutic approaches.

Interleukins-27 Aggravates Liver Injury by Impairing the Antimicrobial Response of Macrophages via the Promotion of Mitochondrial Dysfunction in the Context of Sepsis

Background and Aims: Plasma interleukin (IL)-27 is an important mediator of acute hepatic injury (AHI) associated with sepsis. Mitochondria contribute to the proper regulation of macrophage phagocytosis. In this study, we investigated the effect of IL-27 on mitochondrial function and the antimicrobial response of macrophages in sepsis-associated AHI. Methods: Wild-type (WT) and IL-27 receptor WSX-1 deficient (IL-27R-/-) mice underwent cecal ligation and puncture (CLP). The severity of hepatic injury, inflammatory cytokine levels, hepatic pyroptosis, and bacterial load in the liver and blood were assessed 24 h after CLP. In vitro, RAW264.7 cells and peritoneal macrophages were treated with lipopolysaccharide (LPS) and/or IL-27. The phagocytosis and killing functions of macrophages were detected. Mitochondrial function and mitophagy were detected using western blot, glutathione (GSH)/malondialdehyde (MDA) content measurement, fluorescence staining, and JC-1 staining in vivo and in vitro. After treatment with nicotinamide mononucleotide (NMN, NAD + precursor), a pharmacologic agent that improves mitochondrial function, the inflammatory response, hepatic injury, and hepatic pyroptosis were assessed. Results: IL-27R-/- mice exhibited a marked reduction in hepatic injury, pyroptosis (based on cleaved GSDMD and cleaved Caspases 1 protein levels), and systemic inflammation (based on serum IL-6, IL-10, and TNF-α levels) compared to WT mice following CLP. After CLP, mice lacking IL-27R displayed significantly higher bacterial clearance and greater local infection control. Subsequent studies demonstrated that IL-27 directly impaired the LPS-induced bacterial phagocytosis, killing capacity, and mitochondrial function of macrophages. Finally, enhanced mitochondrial function using NMN in vivo significantly alleviated pathological liver injury and inflammation. Conclusions: These findings indicated that IL-27 impairs the bacterial phagocytosis capacity of macrophages by aggravating mitochondrial dysfunction to aggravate AHI during sepsis.

Bone marrow immune cells and drug resistance in acute myeloid leukemia

In recent years, the relationship between the immunosuppressive niche of the bone marrow and therapy resistance in acute myeloid leukemia (AML) has become a research focus. The abnormal number and function of immunosuppressive cells, including regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), along with the dysfunction and exhaustion of immunological effector cells, including cytotoxic T lymphocytes (CTLs), dendritic cells (DCs) and natural killer cells (NKs), can induce immune escape of leukemia cells and are closely linked to therapy resistance in leukemia. This article reviews the research progress on the relationship between immune cells in the marrow microenvironment and chemoresistance in AML, aiming to provide new ideas for the immunotherapy of AML.

DNA damage-inducible transcript 3 positively regulates RIPK1-mediated necroptosis

DNA damage-inducible transcript 3 (DDIT3) is a well-known transcription factor that regulates the expression of apoptosis-related genes for promoting apoptosis during endoplasmic reticulum stress. Here, we report an unrecognized role of DDIT3 in facilitating necroptosis. DDIT3 directly binds and competitively prevents the p38 MAPK-MK2 interaction and thereby blocking MK2 activation while stimulating p38 MAPK activation. This blockage of MK2 activation initially prevents RIPK1 phosphorylation at Ser320 (inactivation), subsequently relieving its suppression of RIPK1 activation. Consequently, p38 MAPK facilitates RIPK1 phosphorylation at Ser166 (activation) through DDIT3 phosphorylation-related mechanisms, leading to necroptosis. Mechanistically, a 10-amino acid segment (Glu19-Val28) within DDIT3's N-terminus is identified to account for its pro-necroptotic function. In vivo studies demonstrate that forced expression of DDIT3 induces necroptosis, whereas deletion of DDIT3 alleviates necroptosis in mouse hearts under stress. These findings shed light on a novel regulatory mechanism by which DDIT3 promotes RIPK1 activation and subsequent necroptosis.

Confrontation with kidney inflammation through a HMGB1-targeted peptide augments anti-fibrosis therapy

Damage to the renal tubular epithelial cells (TEC) is a key cellular event in kidney inflammation and subsequent fibrosis. However, drugs targeting renal TEC (RTEC) are limited to the alleviation of kidney fibrosis. Lethal giant larvae 1 (Lgl1) plays a key role in epithelial cell polarity and proliferation. Here, we report that the renal tubule epithelial-specific deletion of Lgl1 significantly ameliorated intrarenal inflammation and kidney fibrosis. Mechanistically, Lgl1 suppressed the activity of the deacetylase sirtuin 1 (SIRT1) and augmented the acetylation of high-mobility group box 1 (HMGB1) at the lysine 90 (K90) site. Consequently, HMGB1 migrated from the nucleus to the cytoplasm, activating an inflammatory cascade. Our renoprotective strategy was to construct a mimic peptide, TAT-K90WT, that targets HMGB1 K90 acetylation. Administration of this peptide significantly ameliorated inflammation and fibrosis in the kidneys. In summary, the Lgl1-HMGB1 axis plays an important role in renal fibrosis, and targeting HMGB1 acetylation by mimicking peptides is a potential strategy to prevent fibrosis.

The Role of P53 in Myocardial Ischemia-Reperfusion Injury

PURPOSE

P53 is one of the key tumor suppressors. In normal cells, p53 is maintained at low levels by the ubiquitination of the ubiquitinated ligase MDM2. In contrast, under stress conditions such as DNA damage and ischemia, the interaction between p53 and MDM2 is blocked and activated by phosphorylation and acetylation, thereby mediating the trans-activation of p53 through its target genes to regulate a variety of cellular responses. Previous studies have shown that the expression of p53 is negligible in normal myocardium, tends to increase in myocardial ischemia and is maximally induced in ischemia-reperfused myocardium, demonstrating a possible key role of p53 in the development of MIRI. In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and describe the therapeutic agents targeting the relevant targets to provide new strategies for the prevention and treatment of MIRI.

METHODS

We collected 161 relevant papers mainly from Pubmed and Web of Science (search terms "p53" and "myocardial ischemia-reperfusion injury"). After that, we selected pathway studies related to p53 and classified them according to their contents. We eventually analyzed and summarized them.

RESULTS AND CONCLUSION

In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and validate its status as an important intermediate affecting MIRI. On the one hand, p53 is regulated and modified by multiple factors, especially non-coding RNAs; on the other hand, p53 regulates apoptosis, programmed necrosis, autophagy, iron death and oxidative stress in MIRI through multiple pathways. More importantly, several studies have reported medications targeting p53-related therapeutic targets. These medications are expected to be effective options for the alleviation of MIRI, but further safety and clinical studies are needed to convert them into clinical applications.

Caspase family in autoimmune diseases

Programmed cell death (PCD) plays a crucial role in maintaining tissue homeostasis, with its primary forms including apoptosis, pyroptosis, and necroptosis. The caspase family is central to these processes, and its complex functions across different cell death pathways and other non-cell death roles have been closely linked to the pathogenesis of autoimmune diseases. This article provides a comprehensive review of the role of the caspase family in autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), and multiple sclerosis (MS). It particularly emphasizes the intricate functions of caspases within various cell death pathways and their potential as therapeutic targets, thereby offering innovative insights and a thorough discussion in this field. In terms of therapy, strategies targeting caspases hold significant promise. We emphasize the importance of a holistic understanding of caspases in the overall concept of cell death, exploring their unique functions and interrelationships across multiple cell death pathways, including apoptosis, pyroptosis, necroptosis, and PANoptosis. This approach transcends the limitations of previous studies that focused on singular cell death pathways. Additionally, caspases play a key role in non-cell death functions, such as immune cell activation, cytokine processing, inflammation regulation, and tissue repair, thereby opening new avenues for the treatment of autoimmune diseases. Regulating caspase activity holds the potential to restore immune balance in autoimmune diseases. Potential therapeutic approaches include small molecule inhibitors (both reversible and irreversible), biological agents (such as monoclonal antibodies), and gene therapies. However, achieving specific modulation of caspases to avoid interference with normal physiological functions remains a major challenge. Future research must delve deeper into the regulatory mechanisms of caspases and their associated complexes linked to PANoptosis to facilitate precision medicine. In summary, this article offers a comprehensive and in-depth analysis, providing a novel perspective on the complex roles of caspases in autoimmune diseases, with the potential to catalyze breakthroughs in understanding disease mechanisms and developing therapeutic strategies.

In Silico Characterization of Sirtuins in Acetic Acid Bacteria Reveals a Novel Phylogenetically Distinctive Group

Acetic acid bacteria are single-celled organisms well-known for their ability to convert ethanol into acetic acid. Still, recent research suggests they may harbor another attractive characteristic-the production of proteins with remarkable similarities to sirtuins. Sirtuins have been linked to lifespan extension in various organisms, raising intriguing questions about the potential connection between acetic acid bacteria and the biology of aging. This article delves into the characterization of sirtuin homologs in acetic acid bacteria. Up to three types of sirtuin homologs have been identified in 21% of acetic acid bacteria genomes deposited in NCBI. All three types were present only in the genera Acetobacter and Novacetimonas, which are known to survive in the harshest environmental conditions (high concentrations of acetic acid and ethanol). Interestingly, two types of these sirtuin homologs (SirAAB-L and SirAAB-S) constitute a separate group (SirAAB), distinctive from all other presently known sirtuins. The results obtained in silico thus encourage further studies into the function of these types of sirtuins and their interplay with metabolic pathways in these industrially important bacteria.

Purinergic signaling by TCRαβ+ double-negative T regulatory cells ameliorates liver ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is an important cause of liver injury following liver transplantation and major resections, and neutrophils are the key effector cells in HIRI. Double-negative T regulatory cells (DNT) are increasingly recognized as having critical regulatory functions in the immune system. Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils, as in HIRI, remains largely unknown. In this study, we found that murine and human DNT highly expressed CD39 that protected DNT from extracellular ATP-induced apoptosis and generated adenosine in tandem with CD73, to induce high levels of neutrophil apoptosis. Furthermore, extracellular adenosine enhanced DNT survival and suppressive function by upregulating survivin and NKG2D expression via the A2AR/pAKT/FOXO1 signaling pathway. Adoptive transfer of DNT ameliorated HIRI in mice through the inhibition of neutrophils in a CD39-dependent manner. Lastly, the adoptive transfer of A2ar-/- DNT validated the importance of adenosine/A2AR signaling, in promoting DNT survival and immunomodulatory function to protect against HIRI in vivo. In conclusion, purinergic signaling is crucial for DNT homeostasis in HIRI. Augmentation of CD39 or activation of A2AR signaling in DNT may provide novel therapeutic strategies to target innate immune disorders.

Brain function abnormalities and inflammation in HIV-positive men who have sex with men with depressive disorders

Background

Depressive disorders are highly prevalent among people with HIV (PWH) and are related to aberrant inflammation and immune responses. However, there is currently a lack of investigation into the neurological, inflammatory, endocrine, and immune aspects of HIV-associated depressive disorders (HADD).

Methods

The study involved 33 HIV-positive men who have sex with men with depressive disorders (HADD group) and 47 without neuropsychiatric disorders (HIV control group). Participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans and assessments of peripheral blood. Peripheral blood cytokines, plasma concentrations of hormone and neurotrophic factors, and immune cell levels were determined using liquid chip, enzyme-linked immunosorbent assay, and flow cytometry, respectively. The correlation of imaging alterations with clinical variables and peripheral blood indicators was assessed.

Results

Compared to the HIV control group, the HADD group exhibited a higher fractional amplitude of low-frequency fluctuations in the left superior parietal gyrus, lower regional homogeneity in the left precentral gyrus, and reduced voxel-wise functional connectivity for the seed region in the right precentral gyrus with clusters in the right cuneus, etc. Furthermore, the HADD group had higher levels of interferon-gamma, a higher frequency of non-classical monocytes, and higher expression levels of perforin and CD38 on specific cells. These imaging results were significantly correlated with peripheral blood indicators and clinical variables.

Conclusion

This rs-fMRI study provides considerable evidence for abnormal intrinsic brain activity in people with HADD. Furthermore, our data also indicate the detrimental effects of depression-related inflammation on PWH. Therefore, it is imperative to increase attention to HADD and implement effective preventive interventions accordingly.

Inflammatory adhesion mediates myocardial segmental necroptosis induced by mixed lineage kinase domain-like protein in acute myocardial infarction

PURPOSE

Cardiomyocyte death is a major cytopathologic response in acute myocardial infarction (AMI) and involves complex inflammatory interactions. Although existing reports indicating that mixed lineage kinase domain-like protein (MLKL) is involved in macrophage necroptosis and inflammasome activation, the downstream mechanism of MLKL in necroptosis remain poorly characterized in AMI.

METHODS

MLKL knockout mice (MLKLKO), RIPK3 knockout mice (RIPK3KO), and macrophage-specific MLKL conditional knockout mice (MLKLM-KO) were established. AMI was induced by coronary artery ligation. The role of MLKL in regulating myocardial morphological necroptosis was evaluated using immunofluorescence staining, flow cytometry, qRT-PCR, Western blot, CCK-8 assay, and ELISA.

RESULTS

Our findings revealed that myocardial segmental necroptosis (MSN), a unique morphological characteristics of cell death observed post-AMI, was promoted by intercellular inflammatory adhesion mediated by MLKL. The key features of MSN included localized cytomembrane perforation, segmental attenuation of myofilaments, MLKL-mediated filling, and macrophage inflammatory adhesion. In a mouse model of AMI, we observed MSN, which was absent in immunosuppressed mice. Pharmacological depletion of macrophages or genetic knockout of macrophage-specific MLKL (MLKLM-KO) reduced the occurrence of MSN. This reduction was reversed upon reinfusion of wild-type macrophages. Additionally, myocardial injury was significantly ameliorated in MLKLM-KO mice following AMI. In a macrophage-cardiomyocyte co-culture system, MLKLM-KO attenuated hypoxia-induced MSN and inhibited macrophage-mediated inflammatory adhesion. Furthermore, MLKL was found to trigger the formation of membrane pores and the polymerization of integrin αvβ1, thereby enhancing inflammatory adhesion in the co-culture system. Notably, MLKL-enhanced inflammatory adhesion was not entirely dependent on RIPK3.

CONCLUSION

Our study demonstrates that MLKL is directly involved in myocardial segmental necroptosis by interacting with macrophages through inflammatory adhesion, and possibly independently of RIPK3.

The interaction of tPA with NMDAR1 drives neuroinflammation and neurodegeneration in α-synuclein-mediated neurotoxicity

The thrombolytic protease tissue plasminogen activator (tPA) is expressed in the CNS, where it regulates diverse functions including neuronal plasticity, neuroinflammation, and blood-brain-barrier integrity. However, its role in different brain regions such as the substantia nigra (SN) is largely unexplored. In this study, we characterize tPA expression, activity, and localization in the SN using a combination of retrograde tracing and β-galactosidase tPA reporter mice. We further investigate tPA's potential role in SN pathology in an α-synuclein mouse model of Parkinson's disease (PD). To characterize the mechanism of tPA action in α-synuclein-mediated pathology in the SN and to identify possible therapeutic pathways, we performed RNA-seq analysis of the SN and used multiple transgenic mouse models. These included tPA deficient mice and two newly developed transgenic mice, a knock-in model expressing endogenous levels of proteolytically inactive tPA (tPA Ala-KI) and a second model overexpressing proteolytically inactive tPA (tPA Ala-BAC). Our findings show that striatal GABAergic neurons send tPA+ projections to dopaminergic (DA)-neurons in the SN and that tPA is released from SN-derived synaptosomes upon stimulation. We also found that tPA levels in the SN increased following α-synuclein overexpression. Importantly, tPA deficiency protects DA-neurons from degeneration, prevents behavioral deficits, and reduces microglia activation and T-cell infiltration induced by α-synuclein overexpression. RNA-seq analysis indicates that tPA in the SN is required for the upregulation of genes involved in the innate and adaptive immune responses induced by α-synuclein overexpression. Overexpression of α-synuclein in tPA Ala-KI mice, expressing only proteolytically inactive tPA, confirms that tPA-mediated neuroinflammation and neurodegeneration is independent of its proteolytic activity. Moreover, overexpression of proteolytically inactive tPA in tPA Ala-BAC mice leads to increased neuroinflammation and neurodegeneration compared to mice expressing normal levels of tPA, suggesting a tPA dose response. Finally, treatment of mice with glunomab, a neutralizing antibody that selectively blocks tPA binding to the N-methyl-D-aspartate receptor-1 (NMDAR1) without affecting NMDAR1 ion channel function, identifies the tPA interaction with NMDAR1 as necessary for tPA-mediated neuroinflammation and neurodegeneration in response to α-synuclein-mediated neurotoxicity. Thus, our data identifies a novel pathway that promotes DA-neuron degeneration and suggests a potential therapeutic intervention for PD targeting the tPA-NMDAR1 interaction.

Nanocarriers for siRNA Delivery Aimed at the Treatment of Melanoma: Systematic Review

Melanoma is a malignant skin cancer type with a high lethality rate due to active metastasis. Among the risk factors for its development is exposure to ultraviolet radiation (UV) and phenotypical characteristics such as clear skin and eyes. Given the difficulties of the conventional therapy, the high cost of the treatment and the low bioavailability of drugs, it is important to develop new therapeutic methods to circumvent this situation. Nanosystems such as micelles, liposomes and nanoparticles present advantages when compared to conventional treatments. The objective of this paper is to carry out a literature review based on articles that dealt with the use of siRNA-loaded nanosystems for the treatment of melanoma, with trials carried out in vivo to assess tumor size. The search was conducted in the Web of Science and PubMed databases considering the last 5 years, that is, the period between January 2017 to December 2021. The "SiRNA and Drug Delivery Systems and Melanoma" keywords were used in both databases, and the articles were analyzed using the inclusion and exclusion criteria established for this paper. The results obtained indicated that using siRNA transported via nanosystems was capable of silencing the BRAF tumor genes and of reducing tumor size and weight, not presenting in vitro and/or in vivo toxicity. Such being the case, the development of these systems becomes a non-invasive and promising option for the treatment of melanoma.

ncRNA Editing: Functional Characterization and Computational Resources

Non-coding RNAs (ncRNAs) play crucial roles in gene expression regulation, translation, and disease development, including cancer. They are classified by size in short and long non-coding RNAs. This chapter focuses on the functional implications of adenosine-to-inosine (A-to-I) RNA editing in both short (e.g., miRNAs) and long ncRNAs. RNA editing dynamically alters the sequence and structure of primary transcripts, impacting ncRNA biogenesis and function. Notable findings include the role of miRNA editing in promoting glioblastoma invasiveness, characterizing RNA editing hotspots across cancers, and its implications in thyroid cancer and ischemia. This chapter also highlights bioinformatics resources and next-generation sequencing (NGS) technologies that enable comprehensive ncRNAome studies and genome-wide RNA editing detection. Dysregulation of RNA editing machinery has been linked to various human diseases, emphasizing the potential of RNA editing as a biomarker and therapeutic target. This overview integrates current knowledge and computational tools for studying ncRNA editing, providing insights into its biological significance and clinical applications.